Fig. 1. Cervical spine (C2–C5): Transducer alignment in relation to the cervical spine for ultrasound-guided third occipital nerve block in the transverse view (TV) and the longitudinal view (LV). The  circle indicates the target point. The third occipital nerve crosses the articulation C2–C3 in an anterior-posterior direction at the target point. The  white arrows indicate the movements of the transducer during examination of the neck cranial-caudal in the TV and anterior-posterior in the LV.